1. Field of the Invention
This invention relates to a fluctuation detecting apparatus having the function of calculating a signal corresponding a distance and fluctuation data, and an apparatus with the fluctuation detecting function.
2. Related Background Art
There have heretofore been proposed cameras which effect fluctuation detection by the utilization of automatic focus detecting apparatuses as shown in Japanese Patent Application Laid-Open No. 58-4109 and Japanese Patent Publication No. 5-10603. These cameras effect fluctuation detection by the use of an image pickup element (hereinafter referred to as the AF sensor) the automatic focus detecting apparatus has, and use correlative calculation for image data at a certain time and image data after the lapse of a predetermined time to thereby find the fluctuation amount of the camera.
On the other hand, in recent years, there has been proposed a camera capable of effecting multipoint distance measurement which can measure the object distance in a plurality of areas in a photo-taking image field. Cameras carrying the above-described fluctuation detecting function on such a camera capable of effecting multipoint distance measurement have also been proposed in Japanese Patent Application Laid-Open No. 4-349439, etc. In these cameras capable of effecting multipoint distance measurement and moreover effecting fluctuation detection by the use of the AF sensor, fluctuation detection is effected on the basis of the image data of the AF sensor corresponding to each area (distance measuring point) on which the distance of a main object is measured. Accordingly, fluctuation correction is effected by the use of this fluctuation data, whereby accurate fluctuation correction becomes possible for the main object.
In the fluctuation detection utilizing the above-described conventional AF sensor, the fluctuation of the camera is detected as the image fluctuation amount on the surface of the AF sensor and therefore, whether the detected fluctuation component of the camera is due to the shift fluctuation of the camera in translation directions X and Y or due to the rotation fluctuation in pitch direction P and yaw direction Y cannot be distinguished. Accordingly, when fluctuation correction is to be effected on the basis of the detected fluctuation amount, a fluctuation amount comprising sum of a shift fluctuation component and a rotational fluctuation component is corrected without fail. The rotation fluctuation component is constant in its influence upon the image fluctuation on the surface of the sensor irrespective of the distance of the object, whereas the influence of the shift fluctuation component is varied in the influence on the surface of the sensor by the distance of the object and therefore, when objects differing in distance existed in the photo-taking image field, if detection was effected without the shift fluctuation component and the rotational fluctuation component being separated from each other and fluctuation correction was effected on the basis of that fluctuation amount, accurate correction could not be effected for the objects differing in distance.